Table 1.

Summary of the potential impacts of climate variables on the livestock food supply chain. The nature, extent and magnitude of the impacts will vary depending on a range of factors not described here that may interact in complex ways, such as interactions between climate variables, plant and animal species, agro-ecological conditions and socio-economic contexts.

Supply chain	Potential impacts of climate change
Feed resources	Productivity Regions already water stressed are likely to experience the most negative impacts. Some regions in high latitudes could experience yield increases due to reduced cold stress and longer growing seasons. Soil salinity in coastal regions may increase due to sea level rise and increased frequency and intensity of storm surges. Changing precipitation patterns particularly in arid regions could contribute to greater salinity. Changing weather patterns and warming temperatures could contribute to shifting pest and disease distribution and could increase stress on key pollinator species. Hotter and more humid conditions are likely to result in increased on-farm post-harvest losses where storage conditions are inadequate. Elevated eCO2 can increase yields but won't benefit all crops equally. Temperate C3 species could be the most positively affected, and realised benefits may be mitigated by water and nutrient constraints. Elevated O3 will have a negative effect on yields. Nutritional quality Warmer temperatures and drier conditions will tend to favour C4 species and increase toxicity in some plants, including during storage. Elevated eCO2 could reduce plant protein and mineral concentrations and increase toxicity in some species. Increases in eCO2 will tend to favour C3 plants and woody encroachment at the expense of grasses. Variability in feed availability Inter-annual climate variability is projected to increase globally with overall negative impact on feed production. Changes in seasonal climate patterns will have context specific impacts, which may be positive or negative. However, increased variability will likely lead to less predictable feed supply. Extreme events could restrict animal access to pastures and create larger disruptions to feed production.
Water resources	Hotter and drier conditions are likely to increase water requirements of plants and animals, increasing pressure on water resources, especially in regions already water stressed. Further, warming temperatures will contribute to greater glacier depletion disrupting historical surface water flows. Higher temperatures and extreme events such as floods and droughts are likely to decrease water quality for animal consumption, through increased concentration of pathogens, sediments, salts, nutrients or pollutants in water.
Animal health and production	Animal production, welfare and life expectancy are likely to be negatively impacted, through decreased feed availability and quality, heat stress, diseases (from outbreaks and weakened animal immune system) and mortality from extreme climate events such as storms, floods, heat and cold waves. Globally, the effects are likely to be negative, but in some geographies with cold winters, warmer temperatures may reduce animal cold stress and maintenance energy requirements, as well as housing heating.
Processing, storage, transport and retailing	Higher temperatures, increased humidity, increased frequency of extreme weather events, and rising sea levels are likely to put additional stress on built-up capital (machinery, transportation infrastructure, electricity networks, telecommunications, etc.). Further, warmer temperatures could increase the risk of animal heat stress during transportation, as well as worsen conditions for storage and distribution of food and feed, which could lead to reduced food quality, safety and shelf-life. Increased variability in production and extreme climate events will likely make trade patterns less regular, increasing reliance on complex logistic systems.
Livestock products consumption	Climate change can reduce the availability of livestock products, as well as their quality and safety through contamination with pathogens or pesticide and reduced nutritional quality and sensory appeal. Prices may increase and be more volatile. Changing social norms may impact diets, especially in high-income countries.
Labour	Labour availability and productivity is likely to be negatively impacted by climate change due to heat stress, increased risk of novel disease outbreaks, and extreme events like heat waves, floods and severe storms. Labour is also likely to be negatively impacted by exposure to decreased air quality associated with rising temperatures, nutrition from changes in food supply.
Prices	Costs along the supply chain, commodity price and price volatility are likely to increase under climate change. The impacts of climate change on animal product prices could be felt mainly through changes in costs and availability of feed.